ESGAR 2024 Book of Abstracts

Purpose: Measurements of main pancreatic duct (MPD) diameter and its communication with cystic pancreatic lesions are essential to clinical/radiological management. We compared MRI and EUS MPD diameter measurements and assessed inter-reader reliability (IRR) between 2 MRI readers (R1 and R2) and 1 EUS reader for MPD dilatation and communication with cysts. Material and Methods: Twenty-two patients underwent EUS and MRI within a ≤6-month interval. On EUS, MPD diameter, presence of cysts >5mm and MPD communication were recorded for each patient in pancreatic head, body, and tail. MPD diameter was measured on a predefined single-shot RARE image and presence of cysts on any T2-weighted image. Cyst presence discrepancies were resolved by consensus between R1 and R2. Bland–Altman analysis was used to evaluate MRI vs EUS MPD diameter differences. To assess IRR, Cohen’s kappa ( κ ) was calculated for MPD dilatation (>5mm) and cyst–MPD communication. Results: Mean and 95% limits of agreement (LOA) for MPD

Purpose: This study aims to compare the sensitivity of computed tomography (CT) and magnetic resonance imaging (MRI) in the staging of pancreatic ductal adenocarcinoma and the identification of metastases.Material and Methods: CT and/or MRI images of 119 patients were independently reviewed by two radiologists with different expertise in pancreatic imaging.For each subject, the two readers analyzed the degree of arterial and venous vessel infiltration and searched for any thrombosis and metastases, defining the tumor stage based on the resectability criteria of the National Comprehensive Cancer Network.Intra-and inter-observer agreement was statistically calculated using Cohen's kappa coefficient.Results: Inter-observer agreement in CT was strong for the celiac trunk and hepatic artery infiltration (k=0.66) and moderate for superior mesenteric artery (k=0.54).Inter-observer agreement in the determination of venous vascular infiltration in CT and MRI was respectively moderate (k<0.45) and poor (k<0.22);despite this, the patients' therapeutic paths were correctly distinguished.Furthermore, the intra-observer concordance calculated for the patients for whom both CT and MRI were available highlighted how experience plays an important role in the ability to similarly quantify the degree of vascular infiltration with the two methods.Finally, MRI has proven to be more sensitive than CT in identifying liver metastases.Conclusion: Inter-observer variability in defining the degree of vascular infiltration had a limited impact in determining the resectability of the neoplasm.The different intra-observer concordance in the CT-MRI comparison can be attributed to the different experience.MRI is more sensitive in recognizing liver metastases.SS 1.8 Refining the Classroom: The self-learning professor model for optimized segmentation of locally advanced pancreatic ductal adenocarcinoma J. Bereska, S. Palic, L. Bereska, E. Gavves, Y. Nio, M. Kop, F. Struik, M. Besselink, H. Marquering, J. Stoker; Amsterdam / NL Purpose: The objective of this study is to investigate the frequency of major bleeding in patients with and without cirrhosis who have undergone percutaneous liver procedures (PLP).Additionally, the study aims to explore the relationship between the occurrence of major bleeding and both the gauge of the needle used and the number of needle insertions.Material and Methods: This retrospective study included patients who had scheduled percutaneous liver biopsies (PLB) or percutaneous liver tumor ablations (PLTA) at three centers in Spain.Patients with antithrombotic medications were excluded.Before the procedure, blood tests, including standard coagulation assays, were performed.We recorded demographic, clinical, and technical procedure data.Patients with and without cirrhosis were analyzed separately.The primary outcome was major bleeding.Results: 1797 patients [(1481 without cirrhosis (82%) and 316 with cirrhosis (18%)] that underwent PLP were included.A total of 14 patients (0.8%) experienced major bleeding after the procedure, with no differences between patients with/without cirrhosis; 2 (0.6%) vs 12 (0.8%), respectively (p=1).All bleedings in non-cirrhotic patients were caused by PLB, whereas in cirrhotic patients one case was caused by PLB and another by PLTA.Bleeding was unrelated to the needle gauge in both non-cirrhotic (p = 0.67) and cirrhotic patients (p = 0.48).Similarly, the number of attempts showed no association with major bleeding in either group (p = 1).

Conclusion:
In this cohort study, major bleeding after a PLP was less than 1%, with no significant difference between cirrhotic and non-cirrhotic patients.Neither the number of passes nor the needle gauge was associated with increased bleeding.

SS 2.2
Involution dynamics following microwave ablation of liver tumours W. Weston 1 , O. White 1 , N. Goldberg 2 , J. Shur 1 , E. Johnston 1 ; 1 London / UK, 2 Jerusalem / IL Purpose: To characterise involution of ablation zone (AZ) volumes over time following microwave liver ablation (MWA), and to assess for a relationship with local tumour progression (LTP).Material and Methods: This retrospective observational study included 55 patients (33M, median age 62 years, range 34-84) who underwent MWA of 88 liver tumours.Median follow-up was 304 days (range 21-741).498 manual ablation zone segmentations were performed by a single radiologist using Mint Lesion™ (Heidelberg, DE) on intra-procedural contrast-enhanced CT (CECT) (baseline) scans and subsequently on follow-up diagnostic scans at all available time points (median 5, range 1-9) or until LTP occurred.LTP was defined as new tumour contacting the AZ as determined independently by three radiologists.AZ volume change versus baseline was calculated and plotted over time.Non-linear regression methods, including exponential models, were computed using MATLAB (Mathworks, Natick, USA) to describe AZ involution.Fit equations for two groups (LTP vs no LTP) were compared using an F test.Results: Ablation zone involution was best modelled by mono-exponential decay (adjusted R-square= 0.84, p<0.0005).Ablation zones shrank to approximately 30% of original volume with a 151 day 'half-life' (95% confidence interval: 132-172 days), i.e., >90% of involution occurred by 1 year.No statistically significant difference in volume change was found with or without LTP (F=0.93,p=0.78).Conclusion: Body clearance of microwave liver ablation coagulation zones is independent of LTP and closely follows a mono-exponential decay lasting approximately 1 year.These data might improve 3D image registration-based ablation confirmation algorithms at delayed time points.

Authors' Index
Scientific Sessions SCIENTIFIC SESSIONS / WEDNESDAY, MAY 29, 2024 SS 2.3 Outcome mapping study of trials of transarterial chemoembolization for treating hepatocellular carcinoma: A few concepts measured in too many ways J. Grégory 1 , I. Boutron 2 , P. Créquit 2 , V. Vilgrain 1 , M. Ronot 1 ; 1 Clichy / FR, 2 Paris / FR Purpose: Randomized controlled trials (RCTs) are critical for identifying the best treatment strategy.This study aimed to identify and map outcomes reported in registered and published RCTs of transarterial chemoembolization (TACE) for HCC.Material and Methods: A systematic search was conducted in January 2022 on MEDLINE, EMBASE, and online registries to identify all published or registered RCTs evaluating the efficacy and/or safety of TACE for HCC.Data were collected on the frequency and characteristics of the reported outcome domains and measures.Results: A total of 221 RCTs were identified, including 106 unpublished trials, with a median of 4 [interquartile range, 3-8] outcomes per trial.The number of unique outcome definitions (exclusive of time frame) was 357, distributed among 11 different outcome domains.The most frequently reported domains were survival (78%, 278/357), tumor response (74%, 264/357), and adverse events (68%, 243/357).Among the 357 outcomes, "overall survival" appeared most frequently (47%, 168/357), while 30% of outcomes were evaluated in only one trial.Heterogeneity was found in the definition of outcomes, with 122 measures concerning tumor response, 61 for progression, and 25 for recurrence.Only 4% of outcomes (14/357) were related to quality of life.

Conclusion:
The study identified a broad range of outcomes reported in RCTs of TACE for HCC.These findings highlight the need for standardization of outcome reporting in HCC trials to facilitate comparison and synthesis of evidence across studies.SS 2.4 Beyond the LEGACY study: Yttrium-90 radioembolization for solitary HCC over 8 cm.A retrospective single center analysis G. Gullo 1 , A. Vit 1 , J. Franklin 2 , D. Bitetto 1 , V. Ferrara 1 , M. Sponza 1 ; 1 Udine / IT, 2 Bournemouth / UK Purpose: Yttrium-90 (Y90) transarterial radioembolization (TARE) is a safe and effective treatment for patients with solitary, unresectable HCC.Following the LEGACY study, TARE is offered for patients with HCC <8cm, but there are limited data in similar cohorts with larger HCC.We assessed the safety and efficacy of TARE in HCC treated in our institution, including patients with HCC >8cm.Material and Methods: This was a retrospective single-center cohort study of all patients with solitary HCC treated with TARE in the period 2005-2022, Child-Pugh A and ECOG performance status 0-1.Primary outcome measures were the objective response rate (ORR) and duration of response (DoR) based on modified Response Evaluation Criteria in Solid Tumors (mRECIST) evaluation.Secondarily, we analyzed the overall survival (OS) and progression-free survival (PFS).We performed a subgroup comparison of lesions <8cm and >8cm.
Results: 59 patients were included in the study cohort, 50/59 (84.7%) male, with median age of 71.34/59 (57.6%)HCC were >8cm (median 9 cm) and 25/59 (42.4%) were <8cm (median 5.6cm).No major adverse events were reported.DoR and ORR were 4.4 months (2.0-9.9) and 44.1% (27.2-62.9)for HCC >8cm vs 13.9 months (2.9-20.0)and 73.9% (51.6-89.8)for HCC <8cm (both p=0.032).There were no significant differences demonstrated in OS or PFS.Conclusion: Although treatment responses for patients with tumors >8cm were lower than that for smaller lesions in our cohort and in the LEGACY cohort (median HCC size 2.7cm), a significant proportion of larger HCC still demonstrated a durable treatment response.The benefit of Y90 TARE in larger HCC should be evaluated in prospective trials.SS 2.6 Long-term oncological results of percutaneous radiofrequency ablation for intrahepatic cholangiocarcinoma: A multicentric retrospective study O. Sutter 1 , C. Alitti 1 , A. Rode 2 , H. Trillaud 3 , P. Merle 2 , J.-F.Blanc 3 , L. Blaise 1 , A. Demory 1 , G. N'Kontchou 1 , V. Grando 1 , M. Ziol 1 , P. Nahon 1 , N. Ganne-Carrié 1 , A. Petit 1 , O. Seror 1 , J.-C.Nault 1 ; 1 Bobigny / FR, 2 Lyon / FR, 3 Bordeaux / FR Purpose: The effectiveness of radiofrequency ablation (RFA) in intrahepatic cholangiocarcinomas (iCCA) remains insufficiently studied.Material and Methods: Patients with histologically proven iCCA within Milan criteria treated by percutaneous RFA between 2000 and 2022 in three tertiary centers were included.Primary outcome was overall survival in treatmentnaive patients and secondary outcomes included ablation completeness, adverse events, local and distant recurrence.494 patients with HCC on cirrhosis treated by RFA were included as a comparison group.Results: 71 patients, mostly cirrhotic (80%) with a median size of the main tumor of 24mm were included.Complete ablation was achieved in 93% of cases.Local recurrence was 45% at 5 years, lower in multibipolar-versus monopolar-RFA (22% vs. 55%).Both tumor size (P=0.01)and monopolar RFA (P=0.03) were independently associated with a higher local tumor recurrence.In treatment-naive patients (n=45), median overall and recurrence-free survivals were 26 and 11 months.Tumor size (P=0.01)and Child-Pugh B (P=0.001) were associated with death.The rate of distant recurrences was 59% at 5 years, significantly lower for single tumors <2cm (P=0.002) or <3cm (P=0.02).In cirrhotic patients naïve of previous treatments (n=40), overall survival was shorter in iCCA than in HCC (26 vs. 68 months), with more local recurrences (P<0.0001).Among distant recurrences, 50% were extrahepatic metastases compared to 12% in HCC (P<0.001).Conclusion: Multibipolar-RFA provides better results in terms of local tumor control than monopolar-RFA and could be used to treat small iCCA (<3cm).Adjuvant chemotherapy should be discussed due to the frequent extrahepatic metastasis at recurrence.SS 2.7 Percutaneous cryoablation to control hepatic oligoprogression of advanced pancreatic neuroendocrine tumors R. De Robertis, M. Todesco, E. Bardhi, S. Cingarlini, M. Davì, L. Landoni, M. D'Onofrio; Verona / IT Purpose: To describe early experience with percutaneous cryoablation to control hepatic oligoprogression in patients with advanced pancreatic neuroendocrine tumors (pNETs).Material and Methods: Patients with hepatic oligoprogression and otherwise stable disease who underwent percutaneous cryoablation between September 2022 and September 2023 were included.The procedures were performed under local anesthesia; lesion targeting was performed under US guidance; CT was used for procedure monitoring.Treatment response was assessed with 1-month contrast-enhanced CT; further follow-up was performed with contrast-enhanced MRI.The following endpoints were evaluated: technical success, defined as tumor coverage assessed by intraprocedural CT; procedure effectiveness at 1 month; follow-up findings; complications; and mortality.Results: Thirteen lesions with a mean size of 15±6 mm were treated in 10 patients (8 men, 2 women; mean age 53±8 years).The mean follow-up length was 4±3.8 months.Technical success was obtained in all cases.The 1-month effectiveness rate was 69.2%.No local tumor progression was found over a follow-up of 2.3±2.5 months among completely ablated lesions (9/13).Among incompletely ablated lesions (4/13), tumor debulking was obtained in all cases (mean tumor size reduction, 26±11%); over a follow-up of 7,9±3,5 months, local tumor progression occurred in 3 lesions (tumor size compared to baseline, +29±4%), while 1 lesion had sustained tumor reduction compared to baseline (tumor size, −29%).One patient had post-procedural bleeding that resolved with transcatheter embolization.No deaths were found during follow-up.Conclusion: Percutaneous cryoablation is a feasible, safe, and promising procedure to control hepatic oligoprogression of advanced pNETs; longer followup time is necessary to establish the effectiveness of this procedure.

SS 2.9
Adding short to left gastric arterial embolization for the treatment of obesity: Safety and effectiveness R. Di Giuseppe 1 , B. Hansel 2 , J. Puyraimond-Zemmour 2 , V. Vilgrain 1 , M. Ronot 1 , L. Garzelli 1 ; 1 Clichy / FR, 2 Paris / FR Purpose: Left gastric artery (LGA) embolization has been found to be an effective and safe minimally invasive procedure to achieve sustainable weight loss in trials.This study assessed the safety and effectiveness of a technical modification of LGA that involves adding short gastric artery (SGA) embolization to LGA embolization.Material and Methods: This retrospective single-center study analyzed twenty obese subjects (median age of 53.5 (30-73)) who were not eligible for bariatric surgery and underwent bariatric embolization with 300-500 µm microspheres in addition to participating in a lifestyle counseling program between March 2021 and July 2022.Eight patients had LGA+SGA embolization, and twelve had LGA embolization alone.The primary endpoint was total body weight loss (TBWL) at 6 months in the SGA+LGA and the LGA-only cohorts.Safety was assessed, defined as the 30-day adverse events rate according to the SIR classification.

Conclusion:
In this combined cohort of patients undergoing primary surgery and neoadjuvant treatment, the size criterion in the baseline setting still seems to be the most important factor when predicting nodal positivity in rectal cancer staging, whereas a heterogenous signal, in addition, might prove to be influential.

SS 3.3
Sigmoid take-off to define recto-sigmoid junction and its impact on tumour classification, staging and management A. Augustine, A. Results: Out of 134 rectal cancer patients included, STO-based assessment resulted in reclassification of 13.4% (n=18) cases into sigmoid cancer.There was, however, no change in the stage of cancer.Among these 18 patients, there would have been a change in management in 5 patients had the initial assessment been a sigmoid cancer.There was excellent agreement among the radiologists for both, measuring the distance of STO from the anal verge (ICC = 0.883, p<0.001) and for determining location of the tumour based on STO (K=0.82,p <0.001).

Conclusion:
Use of STO changed location of tumour in 13.4% of high and mid-rectal cancers with likely change in management in one fourths of them.
There was excellent agreement among radiologists for determining STO and for identifying tumour location based on STO.STO can be easily adopted in clinical practice.

SS 3.4
Influence of experience in preoperative staging of rectal cancer G. Sussan Material and Methods: We retrospectively included 109 patients operated for rectal cancer who underwent preoperative MRI from 2014 to 2020.We analyzed rectal staging on MRI and at pathology.MRI staging included the staging performed by the reporting radiologist and an independent assessment performed by one radiology resident.Diagnostic accuracy of the radiologist and the resident were assessed and compared.
Results: Accuracy values of T and N staging and EMVI were similar for the resident and the reporting radiologist, with an inter-reader agreement of 67% for T-staging, 63% for N-staging and 86% from EMVI Overstaging of T-status more commonly occurred for high rectal cancer compared to medium-low rectal cancer for both the resident (0% vs 46%; P = 0.0180) and the radiologist (0% vs 48%; P = 0.0140), while understaging for high rectal cancer vs medium-low rectal cancer was significantly more common for the resident (43% vs 8%; p value: P = 0.0035), but not for the radiologist (14% vs 12%; P = 0.8586).The resident more commonly underestimated the precise N stage compared to the radiologist, while the radiologist more commonly underestimated EMVI status (55% vs 67% Material and Methods: This international retrospective cohort study included consecutive adult patients who underwent resection for solitary HCC and preoperative contrast-enhanced MRI from two tertiary-care hospitals in East Asia and Western Europe.MRIs were independently evaluated by three blinded radiologists at each hospital.Based on LI-RADS v2018, intratumoral fat was defined as "fat in mass more than adjacent liver", and the homogenous subtype as intratumoral fat "in absence of mosaic and nodule-in-nodule architecture".Recurrence-free survival (RFS) and overall survival (OS) were estimated by the Kaplan-Meier method, and prognostic factors were identified by Cox regression analyses.
Intratumoral fat in general was non-prognostic (P range, 0.481-0.973).However, in the Asian cohort, homogenous intratumoral fat was associated with longer RFS (P<0.001) and OS (P<0.001) and remained protective of RFS (HR, 0.60; P=0.010) and OS (HR, 0.33; P<0.001) at the multivariable Cox analyses.Conclusion: MRI-assessed intratumoral fat was more frequent in steatohepatitic HCC and in general non-prognostic.However, homogenous intratumoral fat was an independent protective factor of both RFS and OS in the Asian cohort.Material and Methods: A subset of patients with a diagnosis of Crohn's undergoing therapy who had MRE with motility imaging at two interval time points were selected.Motility index derived from 'cine' images using commercially available software (GIQuant®, Motilent, London, UK) was acquired at the site of most severe disease.This was correlated with radiological features used to assess disease severity in Crohn's (sMaRIA).The change in the motility index between interval studies was correlated with the radiological findings categorised as response, stable disease and progression.Partial response and was documented where there was no change in sMaRIA but improved radiological appearances.
Results: 23 patients (61% male) median (range) age 32 (14-65) years were identified with a median interval of 469 (133-699) days between MRE scans.There was no correlation between sMaRIA score and motility index at baseline (p=0.81)but a negative correlation between absolute and delta values at follow-up (both p<0.01).There was no significant change in the motility index in patients with clinically stable disease.Patients with stable sMaRIA scores but worsening or improved radiological appearances showed correlating motility indices.

Conclusion:
Quantified small bowel motility correlates with the radiological features used to assess Crohn's severity.Findings do not entirely agree with structural features (sMARIA) but appear complementary and agree with overall radiological impression.

SS 5.3
Getting to the score faster: Impact of region of interest type on quantitative scores for small bowel motility in the clinical setting G. Bhatnagar 1 , I. Naim 2 , A. Menys 2 ; 1 Frimley / UK, 2 London / UK Purpose: Quantified small bowel motility, a biomarker for Crohn's Disease (CD), now has clinical applications.Traditionally, GIQuant scores require drawing a polygon region of interest (ROI) around a lesion and transposing it to the motility map.However, many picture archiving and communication systems (PACS) lack this polygon tool, necessitating data transfer to separate readers slowing the process.This study explores using the 'circle' ROI tool, commonly available in PACS, to assess if it yields comparable GIQuant scores.
Material and Methods: In 8 CD patients, a radiologist and imaging scientist placed 32 ROIs (one in each quadrant) using both polygon and circular ROIs.This process was repeated at the same place with a circular ROI which touched the serosa either side of the bowel.Summary statistics were collected along with evidence of associations including i) polygon vs circle GIQuant score and ii) impact of ROI size on difference in GIQuant scores.

Results:
The average polygon GIQuant score was 269.0 (66 to 612) and circle was 269.9 (range 63.6 to 707), difference −0.84, P=0.9.Average polygon area was larger than circles (5.7cm 3 vs 4.3cm 3 ) but non-significantly so, difference −1.38, P=0.33.There were no significant correlations between difference in GIQuant score and difference in ROI area.There was a weak, non-significant correlation (R = −0.27) between circle GIQuant scores and size of circle ROI.

Conclusion:
Circle ROI produced statistically and visually similar GIQuant scores to the previously published polygon ROI score.The circle ROI is widely available on hospital PACS allowing GIQuant measurements to be made in <30s compared to 5-10 minutes where results must be exported to third-party viewers.

SS 5.4
Assessing creeping fat in Crohn's disease through MRE: Interobserver agreement and correlation with disease severity N. Chaniotaki Material and Methods: Three patients undergoing MRI for perianal fistula were selected for this study to capture different and challenging aspects of fistulising disease.Patient 1 has a trans-sphincteric tract with two internal openings in the upper anal canal.Patient 2 demonstrated an intersphincteric fistula in the left posterior quadrant and a trans-sphincteric fistula that opens in the right posterior quadrant.Patient 3 has an internal opening that gives rise to an anterior midline large volume trans-sphincteric tract.There is a secondary tract extending cranially abutting the levator plate that is in close proximity to the urethra.A standard written report along with a 3D model was presented to 17 colorectal surgeons via a web-form displaying the written report followed by the model.Each participant was asked to evaluate their understanding of i) anatomy and ii) clinical decision-making on a score of 1 (low) to 9 (high).
Conclusion: 3D model of fistula anatomy improved clinical understanding of anatomy and clinical decision-making.Interestingly, the high quality of written report was frequently commented on by the surgical reviewers.
Purpose: To investigate the correlation between radiologic and pathologic responses following locoregional and systemic combination therapy, evaluate their prognostic values, and establish a prediction system for pathologic response in patients with unresectable HCC.Material and Methods: This retrospective study included 112 consecutive patients with unresectable HCC who received combination therapy followed by liver resection or transplantation.Radiologic response was assessed with Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and modified RECIST (mRECIST).Performance in predicting pathologic response was assessed with the area under the receiver operator characteristic curve (AUC).
Results: Among radiologic and pathologic response criteria, major pathologic response (MPR, ≤10% residual viable tumors) was the only independent predictor of post-resection recurrence-free survival (RFS) (adjusted hazard ratio 0.34, 95%CI 0.16-0.72,p=0.004).Besides, mRECIST showed stronger correlation with pathologic response than RECIST 1.1 (Spearman r: 0.76 vs. 0.42, p<0.001).A prediction system for MPR was developed that included a combination of mRECIST response (i.e., >70% decrease of viable target lesions) with either >90% decrease in alpha-fetoprotein (AFP) (for AFP-positive group) or >80% decrease in protein induced by vitamin K absence-II (PIVKA-II) (for AFP-negative group), which yielded a respective AUC of 0.905 and 0.887.Moreover, patients with dual-positive response showed improved median RFS (not reached) than those with dual-negative response (7.Purpose: To identify the radiomics features, semi-automatically extracted from MRI-MRCP images, useful to identify patients at higher risk of clinical outcome development. Material and Methods: Fifty-eight primary sclerosing cholangitis (PSC) patients with an MRI-MRCP study acquired with a standardized protocol were prospectively enrolled from Jan-2020 to Dec-2021.Blood tests and liver stiffness measurement (LSM) were collected close to the MRI-MRCP.Patients were classified into high risk or low risk for disease progression using the Mayo risk score (MRS) and LSM.Radiomics features have been extracted using PyRadiomics in each of the five MRI-MRCP sequences analyzed.
Results: Among the 58 patients, 15 (25.0%) and 17 (30.0%)were considered at high-risk using MRS and LSM, respectively.107 radiomics features have been extracted from each MRI-MRCP sequence analyzed.The selection process individuated two features associated with high MRS: neighborhood graytone difference matrix (NGTDM)-busyness in the apparent diffusion coefficient (ADC) and gray-level run-length matrix (GLRLM)-run entropy in T2-spectral presaturation with inversion recovery (T2spir) showing both a mean crossvalidated area under the curve (AUC) of 80%.The multivariable model, including both features, showed an AUC of 87% (SD 11%).When considering LSM (>9.6Kpa) as a stratifier of disease severity, gray level co-occurrence matrix (GLCM)-cluster shade in T1-weighted hepatobiliary phase (T1W HBP phase), GLCM-maximal correlation coefficient in T1W arterial phase, gray-level difference method (GLDM)-large dependence low gray level emphasis in ADC, and GLRLM-run entropy in T2spir showed an AUC of 85%, 83%, 85%, and 92%, respectively.The most accurate multivariable model included three variables: GLDM-large dependence low gray level emphasis in ADC, GLRLM-run entropy in T2spir and GLCM-cluster shade in T1W HBP phase with a median AUC of 96%.

Conclusion:
This proof-of-concept study demonstrates the predictive value of the radiomics features in PSC and their potential role in risk stratification.Data were randomized at 50:50 ratio into a derivation and validation set.Cox regression analysis was used to develop a binary risk classifier and assess the predictive performance for transplant-free survival.Subsequently, the derived risk classifier was applied on the validation set.
Results: 207 patients were included.Median transplant-free survival from MRCP onwards was 6.3 (IQR 3.5-8.8)years and 65 patients experienced an event.Total number of candidate strictures, time from diagnosis to MRCP, proportion of ducts with 3-5mm diameter and center of inclusion were associated with transplant-free survival.The derived risk classifier showed good predictive performance (C-statistic = 0.74) for identifying high-risk patients (HR = 5.4, 95% CI 2.3-12.4,p < 0.001) in the derivation set and remained consistent in 5-fold cross-validation (C-statistic = 0.71).The derived classifier showed comparable predictive performance (C-statistic = 0.69) for risk assessment in the validation set (HR = 3.5, 95% CI 1.7-6.9,p < 0.001).

Conclusion:
This study confirms the additional predictive performance of MRCP+ metrics on long-term transplant-free survival in PSC patients.

SS 7.5
Cholangiocarcinoma in primary sclerosing cholangitis and the importance of MRI: Is our imaging good enough?B. Rea, C. Wright, M. Sukhanenko, D. Gleeson; Sheffield / UK Purpose: MRCP is considered the imaging standard for diagnosis and followup of patients with primary sclerosing cholangitis (PSC).Guidance from the International PSC study group (IPSCSG) highlighted the importance of MRCP technique and outlined a system for grading their quality.In 2017, a "minimum" or "more complete" MR protocol was outlined, and in 2021, a preference for using contrast-enhanced MRI was described.This study's purpose was to review our PSC patients who developed cholangiocarcinoma and assess the quality of their imaging.
Material and Methods: Patients with PSC who developed cholangiocarcinoma from 2014 were identified.Their MRCP protocol and imaging quality for 3 years up to diagnosis were reviewed.Protocols selected were first compared with the 2017 recommendations and classified as "below minimum standard", "minimum standard", or "more complete standard"; and then with the 2021 reporting standards and classified as "preferred protocol" or not.MRCP quality was graded as per IPSCSG reporting standards, with studies graded as good or excellent grouped as "acceptable".
Results: 13 patients with PSC developed cholangiocarcinoma within our 9-year timeframe and 36 MR studies met our inclusion criteria.69.4% of the studies met the 2017 minimum standard protocol, with 22.2% below minimum standard; however, 91.7% did not meet the 2021 preferred standard protocol.Only 39.4% of the MRCPs performed 3 years prior to diagnosis were of "acceptable" quality, with 53.8% of the studies being "acceptable" 1 year prior.Conclusion: MRCP/MRI is central to the diagnosis of cholangiocarcinoma in PSC.However, we frequently found a "minimum protocol" was employed, and our imaging quality was suboptimal, potentially impairing our ability to make an early diagnosis.

SS 7.6
Quantitative The purpose of this study is to evaluate how the identification of the lesion, its extension and vascular involvement can be improved using advanced imaging techniques, through the fusion of diffusion-weighted imaging (DWI) sequences with both T2-weighted sequences and post-contrast T1-weighted sequences acquired in the arterial and venous phases.Material and Methods: A dataset of 48 images, obtained with 1.5 T MRI equipment, was analyzed by two radiologists with different experience.The major axis and vascular involvement were evaluated.For the quantitative variables, the statistical analysis was performed using the pairwise T-test, while for the qualitative variables, the intra-observer and inter-observer agreement was calculated using the Cohen's Kappa test.
Results: From the quantitative analysis, significant differences between the readers were observed in T2-dependent sequences (p=0.04),but not in the fusion images (p=0.4),probably related to a better identification of the lesion in the fusion images and their different experience in abdominal imaging.In the qualitative analysis, intra-observer and inter-observer agreement was found to be minimal for venous vascular invasion for both the readers (K=0.25 and K=0.34), and consequently, image fusion could lead to a better identification of venous infiltration.Conclusion: MR fusion imaging facilitates the evaluation of the extension of perihilar cholangiocarcinoma and vascular infiltration allowing a more precise staging and a better pre-surgical assessment improving therapeutic options.

SS 7.10
Intra-arterial prostate-specific membrane antigen injection using hepatic arterial infusion pump in intrahepatic cholangiocarcinoma, a proof-of-concept study M.M. Veenstra, E. Vegt, M. Segbers, S. Franssen, B. Groot Koerkamp, F. Verburg, M. Thomeer; Rotterdam / NL Purpose: Prostate-specific membrane antigen (PSMA)-targeted tracers show increased uptake in several malignancies, indicating a potential for peptide radioligand therapy.Intra-arterial injection of radiotracers could increase the therapeutic window.This study aimed to evaluate the feasibility of intra-arterial injection of 68 Ga-PSMA-11 for intrahepatic cholangiocarcinoma (ICC) and compare tracer uptake after intrahepatic arterial injection and intravenous injection.
Material and Methods: Patients with pathologically proven inoperable ICC received 68 Ga-PSMA-11 (1,5 MBq/kg body weight) through a hepatic arterial infusion pump, followed by positron emission tomography (PET)/CT.Some days later, patients underwent PET/CT after intravenous 68 Ga-PSMA-11 injection using the same protocols.
Results: Three patients were included.All tumors showed higher uptake on the intra-arterial scan compared with the intravenous scan (intra-arterial/intravenous standardized uptake value normalized by lean body mass (SUL) ratios 1,40-1,54).Uptake in normal liver tissues was similar between intra-arterial and intravenous scans (SUL ratios 0,86-1,13).In addition, 68 Ga-PSMA-11 PET/CT showed diffusely increased uptake in large parts of the liver in one patient that seemed more extensive compared with the recent contrast-enhanced CT.CT three months post-PET/CT showed tumor progression in these exact segments.

Conclusion:
Local intra-arterial PSMA injection is feasible in patients with ICC.
The increased therapeutic window of intra-arterial injection compared with intravenous injection could be an interesting incentive to explore the possibility of PSMA-targeted peptide radioligand therapy for a subset of ICC patients.
Purpose: Total tumor volume (TTV) is associated with overall and recurrencefree survival in patients with colorectal cancer liver metastases (CRLM).However, the labor-intensive nature of such manual assessments has hampered the clinical adoption of TTV as an imaging biomarker.This study aimed to develop and externally evaluate a CRLM auto-segmentation model on contrastenhanced portal venous phase CT scans to facilitate the clinical adoption of TTV.

Material and Methods:
We developed an auto-segmentation model to segment CRLM using 760 portal venous phase CTs (CT-PVP) of 363 patients.We used a self-learning setup whereby we first trained a teacher model on 99 manually segmented CRLM by three radiologists.The teacher model was then used to segment CRLM in the remaining 661 CT-PVPs for training the student model.We used the DICE score and the intraclass correlation coefficient (ICC) to compare the student model's segmentations and the TTV obtained from these segmentations to those obtained from the merged segmentations from three radiologists.We evaluated the student model in an external test set of 50 CT-PVPs from 35 patients with 72 CRLM from the Oslo University Hospital.

Results:
The model reached a DICE score of 0.83 compared to an inter-rater DICE of 0.85.The ICC between the segmented volumes from the student model and from the merged segmentations was 0.97.

Conclusion:
The developed colorectal cancer liver metastases auto-segmentation model achieved a high DICE score and near-perfect agreement (ICC) for assessing TTV.

SS 8.2
Should the term portovenous phase still be used when scanning the liver with Primovist?S. Mokhles, K. Pieterman, M.M. Veenstra, M. Kuijpers, Z. Van Os, H. Muharam, T. Terkivatan, M. Doukas, D. Bos, M. Thomeer; Rotterdam / NL Purpose: The aim is to compare head-to-head washout (WO) after administration of gadoxetate disodium and nonspecific contrast, and to investigate whether liver porta intensity difference (LPID) can be used to determine until when WO can still be assessed.
Conclusion: Only at earliest timepoint PV1 or scantimes with LPID>100 or >200, pseudo-WO (false positives) was minimally present.Missed-WOs (false negatives) were extensively present at all scantimes.We suggest to use the term 'transitional phase' for all portovenous and late phases after gadoxetate disodium contrast injection.

SS 8.3
Efficacy of gadopiclenol in contrast-enhanced MRI of the liver: A post-hoc analysis V. Vilgrain

Conclusion:
Thigh volume repeatability was superior to the L3 skeletal muscle areas, and L3-SMA had 3.7x higher cv.Thigh MFI repeatability was better than for L3-MFI, meaning that smaller muscle changes may be detected in the thighs than in the L3 skeletal muscles.MVZ is distributed around 0; therefore, cv is not suitable.Thigh repeatability is high for patients with liver cirrhosis and in agreement with the literature for healthy volunteers.

Authors' Index
Scientific Sessions SCIENTIFIC SESSIONS / THURSDAY, MAY 30, 2024 8.5 between conventional abdominal diffusionweighted imaging and diffusion-weighted imaging based on deep learning reconstruction: Qualitative and quantitative evaluation O. Ménez, M. Bali, N. Coquelet, J. Absil, V. Denolin, T. Benkert, E. Weiland, T. Metens; Brussels / BE Purpose: This retrospective study aims to evaluate the non-inferiority of accelerated diffusion-weighted imaging (DWI) reconstructed with an experimental deep learning algorithm (DLR-DWI) compared to our standard upper abdomen DWI (S-DWI), in terms of image quality, lesion detection and characterization.Material and Methods: Patients with at least one hepatic or pancreatic lesion were included (waived consent IRB-approved).DWI sequences were acquired in respiratory triggering at 3T (Siemens Vida) with identical parameters (b: 150/800 s/mm 2 acquisition pixel size 2.3x2.3x4mm,Grappa3), except for the number of repetitions leading to a 36% duration reduction and a super-resolution reconstruction algorithm for DLR-DWI.Liver and pancreas sharpness, the presence of noise and artefacts were qualitatively scored (five-grade scale); mean apparent diffusion coefficient (ADC) and standard deviation (SD-ADC) were measured in left and right liver and in the pancreas.Size and ADC were measured in the lesions.Comparisons were assessed with non-parametric tests.Results: 55 patients with 81 lesions were included (26 F, 29 M; age: 64±14 years).On all images and ADC maps, DLR-DWI qualitative scores were significantly superior to DWI scores, besides the artefact score on b-800 images that was not different.In both liver lobes, DLR-DWI ADC values were significantly higher with lower standard deviations (all P<0.008), while not different in the pancreas: left/right liver/pancreas DLR-ADC 1038±169/962±153/1198±193; S-ADC 992±196/932±186/1168±216 10 -6 mm 2 /s.Lesion size, mean ADC and SD-ADC did not differ between the sequences.Conclusion: Compared with S-DWI, DLR-DWI is faster and qualitatively superior.Due to lower noise, ADC values are more elevated in the normal liver parenchyma, while in restricted diffusion lesions, the sequences are equivalent.

SS 8.6
Quantitative T2 mapping for the assessment of acute pancreatitis: A prospective study F. Poroes 1 , N. Vietti Violi 2 , E. Uldry 2 , T. Hilbert 2 , F. Schütz 2 , S. Schmidt Kobbe 2 ; 1 Fribourg / CH, 2 Lausanne / CH Purpose: To evaluate MR-derived pancreatic T2 mapping values in acute pancreatitis (AP) and correlate them with parameters of disease severity.Material and Methods: In a single-center study, we prospectively included 76 consecutive patients with suspected AP between December 2020 and November 2022.The severity of AP was assessed clinically, biologically, and by contrast-enhanced CT (CECT) performed 48-72 h after symptom onset.MRI was also performed at ≤24h after CT.Two radiologists blinded to any clinical information independently evaluated the T2 values by placing three regions of interest inside the pancreatic head, body, and tail on the T2 mapping MR sequence.Results were compared with corresponding CECT images as the gold standard: patient parameters, such as age, gender, and body mass index (BMI); and clinical severity parameters.Inter-reader reliability was determined by calculating the interclass coefficient (ICC).Results: Seventy-six patients (mean age, 52 years ± 18, 39 women) were evaluated.T2 values significantly correlated with the length of hospital stay (P = 0.01), CT severity index (P < 0.001), ICU admission (P < 0.05) and presence of organ failure (P < 0.05).T2 values did not depend on age, gender, BMI, anatomical location (pancreatic head, body, and tail) or main pancreatic duct dilatation.Interreader agreement was good (ICC = 0.85, 95% confidence interval: 0.77-0.90).Conclusion: T2 mapping is useful for assessing the severity of AP enabling differentiation between mild and moderate/severe cases, and, thus, predicting patients at risk of complications and long hospital stays.Compared with current gold standards, T2-mapping offers a non-invasive, non-ionizing, contrastfree alternative.

SS 8.7
Chronic pancreatitis MRI score: A new proposal for diagnosis and disease severity T. Tirkes 1 , D. Yadav 2 , D.L. Conwell 3 , K. Jennings 4 , L. Li 4 , E. Fogel 1 ; 1 Indianapolis, IN / US, 2 Pittburgh, PA / US, 3 Lexington, KY / US, 4 Houston, TX / US Purpose: Generate a new diagnostic scoring system for chronic pancreatitis (CP) using MRI parameters in the well-phenotyped prospective evaluation of chronic pancreatitis for epidemiologic and translational studies (PROCEED) population.We aimed to generate a semi-quantitative composite score that would fulfill the need for a more accurate and early diagnosis of CP.Material and Methods: The magnetic resonance imaging as a non-invasive method for the assessment of pancreatic fibrosis (MINIMAP) study prospectively imaged and analyzed 46 control, 45 suspected, and 46 definite CP patients enrolled at seven clinical centers in the USA from February 2019 to May 2021.Suspected and definite CP diagnoses were established based on imaging findings, symptomatology, and clinical presentation.MRI was performed using a standard imaging protocol on 1.5T Siemens and GE scanners.Logistic regression analysis generated multiparametric CP-MRI score, which included fat fraction (FF), arterial-to-venous enhancement ratio (AVR), and pancreatic tail diameter (PTD).If secretin-enhanced MRCP was performed, pancreatic ductal elasticity (PDE) was added to generate the CP-SMRI score.Results: All MRI and MRCP parameters were significantly different between the control and definite CP cohorts: FF (p<0.001),AVR (p<0.01),PTD (p<0.001) and loss of PDE (p<0.001).Using a multiparametric score yielded better diagnostic performance than the individual parameters.CP-MRI and CP-SMRI had cross-validated area under the curves (AUCs) of 0.84 and 0.86, respectively.The score of 2.6 was 87% sensitive, 68% specific using CP-SMRI and 89% sensitive, 67% specific using CP-MRI for the diagnosis of CP.Conclusion: The multiparametric approach yields higher diagnostic performance to diagnose CP than individual parameters.We propose two comprehensive semi-quantitative criteria that combine three parenchymal MRI features and an optional dynamic secretin-enhanced MRCP feature.Larger population studies with multiple observers and longitudinal analyses are warranted.

SS 8.8
Quantitative analysis of the pancreas with 3D multi-echo Dixon MRI and US point shear wave elastography: Correlations with endocrine and exocrine functions F. Spoto, R. De Robertis, A. Garofano, C. Licata, M. D'Onofrio; Verona / IT Purpose: To evaluate the correlations between proton density fat fraction (PDFF), R2*, volume, and stiffness of the pancreatic parenchyma with endocrine and exocrine pancreatic functions.Material and Methods: On the same day, 117 subjects underwent 3D multi-echo Dixon MRI and transabdominal US point shear wave elastography (pSWE).Whole-gland volumes of interest (VOIs) were segmented on MR images to extract parenchymal volumes and median PDFF and R2* values; nine pSWE measurements were performed, and median values were calculated.The results were compared between the patient's groups (preserved function vs. pancreatic insufficiency and preserved function vs. endocrine insufficiency vs. exocrine insufficiency vs. endocrine and exocrine insufficiency) using the Mann-Whitney test and the Kruskal-Wallis.P values <0.05 were statistically significant.Results: Ninety-three patients were included (50 men and 43 women, mean age 61 years; age range, 18-85 years).28 patients had pancreatic insufficiency (19 endocrine, 4 exocrine, and 5 endocrine and exocrine).PDFF was the only parameter with a significant difference between the groups, being significantly higher in patients with pancreatic insufficiency than in those with preserved pancreatic function (median 7% vs 3,1%, p=0,008).Conclusion: Pancreatic fat content measured by MRI-PDFF is associated with pancreatic insufficiency.

SS 8.10
Correlation between visceral fat volume, sarcopenia and post-operative complications after major pancreatectomy L. Fortuna, M. Bariani, P. Sbeghen, F. Omboni, I. Taama, G. Mansueto, G.A. Zamboni; Verona / IT Purpose: Our purpose was to analyze the correlations between visceral obesity, sarcopenia and post-operative complications after major pancreatic resections.Material and Methods: Informed consent for the utilization of clinical and radiologic data was provided by all patients (PAD-R registry, n1101CESC).We reviewed 255 patients who underwent major pancreatectomy at the Verona Pancreas Institute.We used a commercially available software (Syngo.via,Siemens) to segment visceral fat and paraspinal and psoas muscles at the umbilical level.For each, we logged volume (cm 3 ) and mean density values (HU).We evaluated the presence of post-operative pancreatic fistula (POPF) and post-operative hyperamylasemia (POH).Quantitative variables were described as mean and compared using Student's t-test.p values <0.05 were considered statistically significant.Results: We enrolled 255 patients, 164 M and 91 F, mean age 64 years.Patients who developed a clinically significant POPF (n=106) had a higher visceral fat volume than patients without a clinically significant POPF (n=149) (p<0.0001).Patients with POPF had a higher muscle volume than patients without a significant POPF (p= 0,0106).No difference was observed in muscle density between POPF and non-POPF patients.No difference was observed in visceral fat or muscle volume between patients who developed post-operative hyperamylasemia or not.Conclusion: In our series, visceral fat was correlated with the onset of postoperative pancreatic fistula, especially clinically significant fistula.Purpose: To retrospectively collect radiomic data from preoperative rectal MR and determine their possible relationship with response to neoadjuvant treatment.
Material and Methods: 88 patients with biopsy-proven advanced rectal adenocarcinoma and staging MR were enrolled.After neoadjuvant therapy and rectal anterior resection, tumour regression grade (TRG) was collected: TRG 1-2 were classified as responders, while TRG 3-5 as non-responders.Texture analysis was conducted by LIFex software on T2-weighted para-axial MR sequences, and a region-of-interest was manually drawn on a single slice.
Features with a Spearman correlation index >0.5 have been discarded and a LASSO feature selection has been applied.Selected features were trained using bootstrapping.

SS 9.5
The comparison of conventional diffusion-weighted imaging versus diffusion kurtosis imaging and amide proton transfer-weighted imaging in evaluating response to neoadjuvant therapy in rectal cancer: A prospective study X.Gong 1 , X. Zhang 2 , B. Song 1 ; 1 Chengdu / CN, 2 Wuhan / CN Purpose: To assess the efficacy of diffusion kurtosis imaging (DKI) and amide proton transfer (APT)-weighted imaging in distinguishing pathological complete response (pCR) following neoadjuvant therapy in patients with rectal cancer (RC), compared to conventional diffusion-weighted imaging (DWI).
Material and Methods: A total of 83 patients with biopsy-proven RC treated with neoadjuvant therapy were prospectively recruited.All individuals underwent preoperative MR scans, including T2-weighted and the above three sequences.
According to the pathology, participants were grouped into pCR and non-pCR groups.DKI parameters, including mean diffusivity (MD) and mean kurtosis, APT-weighted signal intensity, and mono-exponential apparent diffusion coefficient (ADC) values were calculated and analyzed between the groups.

Conclusion:
Preoperative ADC value may serve as a more valuable imaging biomarker for non-invasively predicting pCR in RC patients undergoing neoadjuvant therapy than DKI and APT-weighted imaging metrics.Purpose: To assess the accuracy of post-neoadjuvant therapy (NAT) MRI for involvement of the anal sphincter in comparison with pathology in rectal cancer.
Material and Methods: This is a retrospective study including 49 patients with the involvement of anal sphincter by rectal cancer at baseline MRI undergoing NAT followed by post-NAT MRI.Two GI specialized radiologists reader 1 (R1) with 20 years and reader 2 (R2) with 1 year of experience reviewed both MRIs and assessed the involvement of anal sphincter by tumor at baseline and by tumor and scar after NAT.32 (65%) patients had surgical resection after NAT, and pathology was reviewed by a GI specialized pathologist to assess involvement of anal sphincter.Rater agreement between the radiologists, and pathologist, was assessed using Cohen's kappa.
Results: There was moderate agreement between readers for involvement of anal sphincter at baseline (kappa 0.53) and fair agreement at post-NAT MRI (kappa 0.31).There was moderate agreement between R1 and pathologist (kappa 0.55) and between R2 and pathologist (kappa 0.53).When comparing agreement between R1, R2 and pathologist for type of involvement of anal sphincter, there was slight agreement for the presence of scar (kappa 0.12 and 0.09), fair agreement for the presence of tumor for R1 (kappa 0.25) and no agreement for R2 (kappa −0.32).Conclusion: Both radiologists had good agreement for involvement of anal canal post-NAT in rectal tumor compared to the pathology with slightly better accuracy for tumor involvement by the most experienced reader which may reflect years of training.

SS 9.7
Creating machine-learning response-assessment models with robust ground-truth labels through innovative fusion of rectal MRI and whole-mount histopathologic specimens N. Horvat 1 , J.M. Santos 1 , J. Heiselman 1 , C. Firat 1 , T.H. Kim 1 , J. Chakraborty 1 , A. Assuncao 2 , J. Shia 1 , J. Garcia-Aguilar 1 , M.J. Gollub 1 ; 1 New York, NY / US, 2 Sao Paulo / BR Purpose: MRI-based radiomics holds promise as an objective tool for predicting treatment response in the context of rectal cancer.However, its current clinical utility remains limited by its generalizability.Specifically, radiomic models have yet to be trained using whole-mount histology (WMH) as the ground truth, even though WMH is considered the gold-standard reference method for point-by-point comparison.This study assessed a rigid point-based registration method to evaluate the WMH and MRI fusion accuracy.Material and Methods: 18 consecutive patients with RC who underwent neoadjuvant therapy followed by total mesorectal excision from 2018 to 2021 were included.A multimodal radiology-pathology-image-registration workflow was developed.1) Tumor bed, internal and external borders of the rectum, and eight corresponding landmarks were manually delineated on MR and WMH images by a radiologist and a pathologist, respectively.2) Rigid point-based registration of images with automated rescaling was computed via the delineated landmarks.3) Biomechanically constrained plane strain elastic deformable registration was computed from the initial rigid alignment between the annotated contours to account for MR and WMH rectal distension differences.4) We performed image registration using a combination of in-house rigid registration, active contours, and finite-element software.5) Outputs from the multimodal image fusion system were rendered in 3D Slicer.
Results: Dice overlap and modified Hausdorff distance of the delineated MR and pathology images showed a significantly good correlation between external and internal border segmentations (P values˂.05, comparing  The study then focused on the influence of radscore on radiologists' subjective evaluations during rectal cancer re-staging.We retrospectively analyzed 60 patients (20 with pCR and 40 without) in a two-phase approach: initially using only mrTRG, followed by a combined assessment with mrTRG and radscore.This involved two junior and two senior radiologists, examining intra/ inter-observer variability and the accuracy of pCR prediction.
Results: The integration of radscore with mrTRG led to a significant improvement in the accuracy of pCR prediction, increasing from 75% with mrTRG alone to 88% when combined with radscore (p<.Material and Methods: Statements (the Q-set) on barriers and facilitators to proforma use were developed from a previous interview study.Radiologists across a regional bowel cancer improvement programme (population 5.7 million) were invited.Participants electronically sorted the statements in a forced normal distribution according to their beliefs (q-sort).Factor arrays were created from the data analysis to identify shared viewpoints.
Results: Twenty-six radiologists completed a q-sort representing nine hospital trusts.Three distinct viewpoints were identified, explaining 50% of variance.
( Material and Methods: The proposed virtual-VMFF is defined as the ratio of estimated fat mass to expected liver mass.The estimated fat mass is calculated using a density of 0.911 for liver voxels with attenuation below zero, and 0.955 for those between zero and mean splenic attenuation.The expected liver mass is derived from a density of 1.079 applied to the liver's volume. The dataset, comprising data from 145 adult patients, was utilized to compare the proposed method with existing methods, which are liver attenuation<40 HU and liver/spleen attenuation ratio<1.0.The study utilized commercial body composition analysis software for all analyses (DeepCatch v1.X, MEDICAL IP Co., Ltd.).
Results: The correlation between the proposed virtual-VMFF and the average liver attenuation and liver-spleen attenuation ratio in the first dataset was evaluated using the R-squared value, which showed strong correlations of 0.96 and 0.85, respectively.The proposed virtual-VMFF was 4.39% for an average liver attenuation value of 40 HU and 3.60% for a liver-spleen attenuation ratio of 1.0.

Conclusion:
In this study, we proposed the virtual-VMFF as a method for quantifying the mass of abnormal areas in the liver.Our findings demonstrated that virtual-VMFF correlates well with existing methods, showcasing its potential as a promising tool in the quantification of liver fat using CT images.

SS 10.4
Advanced CT-derived imaging markers for predicting cardiometabolic health risks: Insights from seven years of cohort data analysis S.J. Park

Conclusion:
This study demonstrates the potential added value of WB-MRI in the search for the underlying primary tumour in the complex diagnostic workup of patients with disseminated adenocarcinoma of unknown primary.

SS 11.2
Searching for the primary tumour in patients with cancer of unknown primary using fluorodeoxyglucose positron emission tomography/CT: A systematic review and individual patient data meta-analysis J. Willemse 1 , D. Lambregts  CgA) and Ki-67%] were analyzed, using progression-free survival (PFS) as the reference.Responders (R) were defined as those with PFS > 6 months.
Conclusion: Survival analysis highlights the need for tailored response criteria, demanding a comprehensive assessment of CgA, ADC values, and tumor size to effectively monitor CAPTEM response in hepatic metastasized NETs.
Purpose: Peptide receptor radionuclide therapy (PRRT) has a major place in the treatment of metastatic neuroendocrine tumours (NETs).Its efficacy is generally evaluated after four cycles (C), with no early predictor identified to date.During each PRRT cycle, 177 Lu-related gamma emissions can be measured by post-PRRT scintigraphy.We explored whether the variation in tumor uptake on post-PRRT scintigraphy performed at C1 and C2 could predict the efficacy of PRRT.
Material and Methods: We studied all patients who received at least two cycles of PRRT (2013-2019) for metastatic NET.We calculated the C2/C1 ratio of liver metastases uptake (geometric mean of anterior and posterior uptakes) on post-PRRT scintigraphy.We explored the association between the C2/C1 ratio and the response evaluation criteria in solid tumors (RECIST)-defined response after C4 and progression-free survival (PFS).

Conclusion:
The evolution of NET uptake between C1 and C2 is a simple tool for early prediction of PRRT efficacy.This biomarker, if confirmed prospectively, could help identify early the patients who may benefit from the treatment optimisation or change.Material and Methods: A retrospective analysis included 29 patients with 62 target lesions undergoing everolimus treatment and pre-therapy, and followup 68 Ga-DOTA-TATE (-TOC) PET/CT scans.Response evaluation utilized progression-free survival (PFS) categorized as responders (R; PFS > 6 months) and non-responders (NR; PFS ≤ 6 months).Lesion size and density, along with standardised uptake value (SUV) in target lesions, liver, and spleen, were assessed.Tumor-to-spleen (T/S) and tumor-to-liver (T/L) ratios were calculated.
Results: PET/CT scans were acquired 19 days (IQ 69 days) pre-treatment and 127 days (IQR 74 days) post-starting everolimus.The overall median PFS was 264 days (95% CI: 134-394 days).R exhibited significant decreases in Tmax/ Lmax and Tmean/Lmax ratios compared to NR (p=0.01).In univariate Cox regression, Tmean/Lmax ratio was the sole prognostic parameter associated with PFS (HR 0.5, 95% CI 0.28-0.92,p=0.03).Percentage changes in T/L and T/S ratios were significant predictors of PFS, with the highest area under the curve (AUC) for the percentage change of Tmean/Lmax (AUC=0.73).An optimal threshold of < 2.5% identified patients with longer PFS (p=0.003).No other imaging or clinical parameters were predictive of PFS.

Conclusion:
This study highlights the potential of quantitative somatostatin receptor positron emission tomography (SSTR-PET)/CT in predicting and monitoring everolimus response in NET patients.Liver metastasis-to-liver parenchyma ratios outperformed size-based criteria, and Tmean/Lmax ratio may serve as a prognostic marker for PFS, warranting larger cohort investigation.
SS 11.7 Validation of the standardisation framework somatostatin receptor positron emission tomography reporting and data system 1.0 for neuroendocrine tumours using the novel somatostatin receptor-targeting peptide [18F]SiTATE R.K. Ebner; Munich / DE Purpose: Somatostatin receptor positron emission tomography (SSTR-PET)/ CT using [68Ga]-labelled tracers is a widely used imaging modality for neuroendocrine tumours (NET).Recently, [18F]SiTATE has shown great potential due to its favourable clinical characteristics.We aimed to evaluate the reproducibility of SSTR reporting and data system (SSTR-RADS) 1.0 for structured interpretation and treatment planning of NETs using [18F]SiTATE.
Material and Methods: Four readers assessed [18F]SiTATE-PET/CT of 95 patients according to the SSTR-RADS 1.0 criteria at two different time points.Each reader selected and evaluated up to 5 target lesions per scan.Overall scan score and the decision on peptide receptor radionuclide therapy (PRRT) were considered.Inter-and intrareader agreement was determined using the intraclass correlation coefficient (ICC).
Results: Interreader agreement for identical target lesions (ICC≥85%), overall scan score (ICC≥90%) and decision to recommend PRRT (ICC≥85%) showed excellent agreement.However, significant differences were observed in recommending PRRT within ERs (p =0.020) and IRs (p =0.004).Compartmentbased analysis demonstrated good to excellent interreader agreement for most organs (ICC≥74%), except for lymph nodes (ICC≥52%).Conclusion: SSTR-RADS 1.0 represents an accurate and reproducible framework system for stratifying [18F]SiTATE-PET/CTs as an alternative for [68Ga]labelled PET/CTs in NET-imaging.However, excellent interreader agreement on the overall scan score and the decision for PRRT was observed, and there were variations in PRRT recommendations, highlighting the complexity of such decisions, suggesting the need for a multidisciplinary input.Compartment-based assessments demonstrated excellent interreader agreement for the liver, soft tissue, and skeleton, with varying agreement for lymph nodes, emphasising the importance of functional imaging for small lesions.The aim of the study was to evaluate whether radiomics, through the analysis of the features obtained from the texture analysis of different pancreatic tumors, was able to predict the histotype; in particular, ductal adenocarcinomas and neuroendocrine tumors were compared.
Material and Methods: Contrast-enhanced CT scans of 193 patients were retrospectively reviewed and a total of 97 adenocarcinomatous lesions and 96 neuroendocrine lesions were analyzed.Furthermore, anamnestic data (smoking habits, diabetes, and jaundice) and clinical data (CA19-9, gastrin, serotonin, insulin, C-peptide, and alpha-feto protein) were evaluated.107 features were extracted for the arterial and venous phases, and receiver operating characteristic (ROC) curves were constructed for the parameters that proved to have the highest area under the curve (AUC) for two groups, the first including all the lesions and the second including only the lesions smaller than 5 cm.
Results: The following differences in features were found to be statistically significant (p < 0.05).Not discriminating the dimensions: for the arterial phase, 16 first-order and 38 second-order features; for the venous phase, 10 first-order and 20 second-order features.Considering instead the lesions with axes less than 5 cm: for the arterial phase, 16 first-order and 52 second-order features; for the venous phase, 11 first-order and 36 second-order features.
Conclusion: Texture analysis of pancreatic pathology has demonstrated good predictability in defining the neuroendocrine histotype and is worthy of further investigation.
Purpose: To compare diagnostic performance of MRI, CT, endoscopic US (EUS), positron emission tomography (PET)/CT and different combinations for initial staging of esophageal cancer.
Material and Methods: In this prospective study, we included 60 patients between 10.2017 and 12.2021 (M/F 50/10, mean age 66 ± 9 y.o.) with newly diagnosed esophageal cancer.Each patient underwent a 3T MRI in addition to the standard staging procedures (EUS, CT and fluorodeoxyglucose positron emission tomography (FDG-PET)/CT) for initial staging.Two independent readers (except for EUS) were asked to determine T-stage using MRI, CT and EUS, N-stage using MRI, CT, PET/CT and EUS, and M-stage using MRI, CT and PET/CT.Consensus was obtained in case of discordance using a third reader.The reference standard was the histopathology of the surgical specimen or TNM-staging established during tumor board meeting.Diagnostic performance of procedures was analyzed separately and in combination.
Results: For T-stage, area under the curve (AUC) for classifying tumors (T1-T3) versus (T4) was 0.83 for MRI, 0.80 for EUS and 0.74 for CT.For N-stage, AUC for classifying N0 versus N+ was 0.78 for MRI, 0.78 for EUS, 0.75 for CT and 0.84 for PET/CT.For M-stage, AUC for classifying M0 versus M+ was 1 for MRI and PET/CT and 0.7 for CT.AUC to differentiate T1-2N0M0 from T3-4N1-3M0-1 was 0.92 for MRI+PET/CT and 0.78 for EUS+CT+PET/CT (p-value 0.357).Conclusion: MRI is highly accurate for the initial TNM staging enabling the optimal assessment of adjacent organ invasion.PET/CT and MRI are optimal combination to separate curative versus palliative patients.
static LPLN using a 5-point confidence scale in the DC.The least absolute shrinkage and selection operator regression analysis was conducted to select predictive radiomics and clinical features in the DC.Radiomics and clinicalradiomics models were constructed and externally validated using the VC, and their diagnostic performance was compared with the radiologists' assessments using receiver operating characteristic curve analysis.Results: Metastatic LPLN was histopathologically proven in 35.4% (65/190) and 32.9% (48/146) in the DC and VC, respectively.The radiomics model's performance (area under the curve [AUC]: 0.875) and the clinical-radiomics model's performance (AUC: 0.873) were significantly better than that of the radiologists (AUCs: 0.620 and 0.676) in predicting metastatic LPLN in the DC (Ps<0.05).In both DC and VC, there was no significant difference in AUCs between the radiomics (0.875 and 0.821) and clinical-radiomics models (0.873 and 0.829) (P>0.05).Conclusion:The MRI-based radiomics model outperforms experienced radiologists in predicting LPLN metastasis in rectal cancer patients, offering a noninvasive biomarker for personalized surgical treatment.(OR27.92;.Positive associations could still be demonstrated when using the factors included in the ESGAR consensus criteria, although only size ≥5 mm remained statistically significant (multivariable OR 10.13; 95%.When applying the ESGAR consensus criteria to create a binary variable, the OR of malignant outcome for lesions with a positive ESGAR status was 8.39 (95% CI 2.21-31.9).
Defining the tumor location in rectal cancer -Main variations in practice and their potential impact F. Goedegebuure, F. Arico, M. Lahaye, M. Maas, G. Beets, R. Beets-Tan, D. Lambregts; Amsterdam / NL ). Conclusion: Accuracy of TN staging and EMVI assessment of rectal cancer on MRI is still moderate.Expertise in rectal MRI allows to reduce both overstaging of T-status for high-rectal cancer and understaging of N-status, but did not improve EMVI assessment.SS 3.5 AI-accelerated T2-weighted turbo spin echo imaging of the rectum, image quality and acquisition time compared to standard T2-weighted turbo spin echo imaging J. Shur 1 , O. White 1 , F. Castagnoli 1 , G. Hopkinson 1 , E. Scurr 1 , B. Whitcher 1 , G. Charles-Edwards 1 , J. Winfield 1 , D.-M.Koh 2 ; In 17% of clinical guidelines, tumor location is not defined or included in the recommendations.100% of radiological guidelines recommend to measure tumor height from the anorectal junction; 83% recommend the anal verge as an additional (or alternative) landmark.Only 33% of radiological guidelines provide thresholds to classify tumors as low/middle/high.Conclusion:This review shows that there is substantial variation in modalities, definitions and landmarks used to classify rectal tumor location.Considering its impact on treatment planning, this highlights the need for more standardized methods that are better aligned between clinical and radiological guidelines.SS 3.7Impact of endorectal filling on rectal cancer staging in magnetic resonance imaging (MRI) G. Sussan 1 , C. D'Alessandro 1 , A. Micelli 1 , P. Santini 1 , C. Dal Magro 1 , J. Zambon Bertoja 1 , F. Crimì 1 , E. Quaia 1 , F. Vernuccio 2 ; 1 Padua / IT, 2 Palermo / IT Purpose: The use of endorectal filling (EF) for MRI staging of rectal cancer is debated.About one third of the panelists of the 2018 ESGAR guidelines for clinical management of rectal cancer recommend rectal filling, while the majority do not.The aim of our study was to compare the diagnostic accuracy of MRI with and without EF for TN-staging and assessment of extramural vascular invasion (EMVI).Material and Methods: We retrospectively included 210 patients operated for rectal cancer from 2007 and 2020 who underwent a clinical MRI of the rectum for preoperative staging.The study cohort was divided into patients who received EF before the pre-operative MRI (EF-MRI group) and those who did not (non-EF-MRI group).Using pathology as reference standard, we compared the accuracy of preoperative MRI, with and without the EF, for T-staging, N-staging and EMVI.Results: The accuracy of MRI for T-and N-staging was similar in the EF-MRI group and the non-EF-MRI group (Conclusion: SMS significantly reduced MRI scan times while maintaining reliable diffusion metrics.IVIM-derived D and DKI-derived MK outperformed ADC in predicting MVI and the histologic grade of HCC, and are associated with an increased risk of early tumor recurrence.SS 4.7Prognostic implications of MRI-assessed intratumoral fat in hepatocellular carcinoma: An international dualcenter study H. Jiang 1 , R. Cannella 2 , Z. Wu 1 , A. Beaufrère 3 , M. Dioguardi Burgio 3 , R. Sartoris 3 , Y. Wang 1 , Y. Qin 1 , J. Chen 1 , Y. Chen 1 , W. Chen 1 , Y. Shi 1 , B. Song 1 , M. Ronot 3 ; 1 Chengdu / CN, 2 Palermo / IT, 3 Clichy / FR Purpose: Intratumoral fat is frequently detected in HCC with reported prognostic value.Therefore, we aimed to investigate the clinical-pathological-radiological correlations and prognostic implications of MRI-assessed intratumoral fat. Comparison of the diagnostic performance of European (ESGAR) vs North American (SRU) 2022 ultrasound gallbladder polyp management guidelines for ≥ 7mm polyps B.P. Nanda 1 , B. Moloney 2 , A. Gershon 1 , H.-J. Jang 1 , K. Elbanna 1 , X. Liu 1 , K. Nowak 1 , K. Khalili 1 ; 1 Toronto, ON / CA, To compare the diagnostic performance of 2022 ESGAR/EAES/ EFISDS/ESGE vs Society of Radiologists in Ultrasound's (SRU) 2022 gallbladder polyp (GBP) management guidelines for polyps of ≥7mm.Material and Methods: All patients who with ≥7mm polyp reported on available US scans at a hepatobiliary center with eventual cholecystectomy over a 20-year period were included.2-5 images from the earliest available scan were selected for review by 4 blinded abdominal radiologists (3-23 years' experience).Shape (thin stalk/thick stalk/sessile), wall thickening and size were used to classify imaging features and along with relevant clinical features (age, ethnicity, PSC) formed the ESGAR and SRU binary management categories of no follow-up/follow vs refer-to-surgeon.Pathology reports were classified according to WHO 2017 by a staff pathologist, with outcome for management defined as polyps requiring resection (PRR, all neoplasms).Kumar 1 , A. Plumb 1 , S. Mallett 1 , C. Clarke 1 , T. Parry 1 , J. Weng 1 , G. Bhatnagar 2 , S. Bloom 1 , J. Hamlin 3 , A. Hart 1 , S. Travis 4 , R. Vega 1 , M. Hameed 1 , A. Bhagwanani 2 , R. Greenhalgh 1 , E. Helbren 5 , J. Stephenson 6 , I. Zealley 7 , V.N.Eze 8 , J. Franklin 9 , A. Corr 1 , A. Gupta 1 , D. Tolan 3 , W. Hogg 3 , A. Higginson 10 , T. Raine 11 , L. Lee 6 , R. Pollok 1 , J. Patel 1 , S. Halligan 1 , S.A. Taylor 1 , METRIC-EF Study Investigators 1 ; Quantified motility and structured anatomical scoring in clinical practice -A real world investigation of emerging markers of small bowel Crohn's disease activity G. Bhatnagar, A. Bhagwanani, A. Menys, I. Naim, T. Shepherd, S. Rahman; London / UK Purpose: Quantified small bowel motility has transitioned from being a research tool into the early stages of clinical practice for assessing small bowel Crohn's Disease activity.We compare findings with simplified MAgnetic Resonance Index of Activity (sMARIA) in a group of patients undergoing MR enterography.
2Salthill / IE Purpose: Results: 135 patients (mean age 53.3, range 20-86, 59 female (42.8%)) with median polyp size 10mm (range 7-45) formed the study cohort.27/138(20.0%) of patients had PRR (5 pyloric gland adenoma, 8 intracholecystic papillary neoplasm, 12 carcinoma in situ/carcinoma, 2 Mets).Intra-observer variability (SRU-risk) kappa values for 4 readers were 0.50/0.52/0.60/0.95(moderate-almostperfect).Mean kappa for interobserver agreement was 0.37 (range 0.28-0.48,fair-moderate).Mean accuracy/sensitivity/specificity (range) for the detection of polyp requiring resection were ESGAR 50%(47-53%)/90%(85-96)/40%(38-42) and SRU 85%(84-87)/61%(59-63)/90%(89-93).The differences between the mean accuracy/sensitivity/specificity of the two guidelines were significant (p= 0.03, <0.001, <0.001, respectively).Conclusion: Regarding the detection of PRR at presentation, ESGAR management guidelines are significantly more accurate with high sensitivity, while SRU's are more specific resulting in fewer unnecessary recommendations for surgery but more follow-up of PRR.SS 4.9The significance of contrast enhancement ratio in differentiation of gallbladder cancers from complicated cholecystitis F. Kulali; Istanbul / TR Purpose: Patients with gallbladder cancers have poor prognosis.They can mimic complicated cholecystitis.Pre-operative early and accurate diagnosis is essential.Therefore, our aim was to investigate the significance of contrast enhancement ratio (arterial phase/pre-contrast) on MRI in differential diagnosis of cancer and complicated cholecystitis.Material and Methods: A total of 76 patients who had complicated cholecystitis with a suspicion of gallbladder cancer in pre-operative abdominal MRI reports during a retrospective 48-month period were included in this study.All patients had histopathological results.Imaging features (size, wall thickness, wall irregularity/discontinuity, signal intensities, contrast enhancement ratio and restriction of diffusion) were evaluated.The relationship between MRI and histopathological findings was statistically analyzed.Results: Of 76, 36 (a mean age of 50±13 years, 18 men and 18 women) had only complicated cholecystitis whereas 40 patients (a mean age were found significant for malignant group (p < 0.05).Conclusion: Detailed MRI evaluation with awareness of high arterial contrast enhancement ratio and lower ADC value which indicate malignancy is important especially in patients with complicated cholecystitis.Purpose: To develop and internally evaluate a multivariable prediction model comprising both clinical predictors and predictors based on MRE to improve prediction of disabling Crohn's disease (CD) within 5 years of diagnosis.Material and Methods: In this multicentre, prospective study across 9 UK hospitals, we assessed the comparative predictive ability of prognostic models incorporating magnetic resonance enterography (MRE) scores [MRE Global Score (MEGS), simplified MAgnetic Resonance Index of Activity (sMaRIA) and Lémann Index] versus models using clinical characteristics alone, e.g.age, smoking, disease location, blood/stool markers, to predict disabling (severe) CD (modified Beaugerie definition) within 5 years of diagnosis.Results: We studied 194 newly diagnosed patients, median age 29, IQR 22 to 44 years, 48% male.Within 5 years from diagnosis, 42% (81/194) of participants developed disabling disease.In the univariable analysis, initial requirement for steroid therapy was associated with a higher risk of developing disabling disease].The baseline clinical model had 52% (41-62) sensitivity and 69% (59-76) specificity for predicting the top 40% of patients with the greatest risk of developing disabling disease, and 86% (77-92) sensitivity and 35% (27-45) specificity for predicting patients with an absolute risk of developing disabling disease of greater than or equal to 10%.There was no difference in sensitivity between models incorporating MEGS, sMaRIA and LI compared to the baseline clinical models.Conclusion: Addition of MRE activity/bowel damage scores to a multivariable model comprising existing clinical predictors did not improve prediction of disabling CD.
1, M. Karachaliou 1 , A. Karatzas 1 , C. Triantos 1 , C. Kalogeropoulou 1 , S. Gourtsoyianni 2 ; 1 Patras / GR, The aim of this retrospective study was to visually assess the volume and distribution of creeping fat (CF), a potential independent factor during Crohn's disease (CD), in MR Enterographies (MREs) and correlate it with simplified MAgnetic Resonance Index of Activity (MARIAs) score.Material and Methods: Reports from 308 (234 conducted in an academic institution from 2019 to 2023 +74 in a private practice from 2014 to 2023) MREs performed in patients with endoscopically suspected or confirmed CD, reviewed by experienced GI Radiologists, were included.Twenty-five exams (23 patients) with reported creeping fat were identified and independently assessed by one experienced radiologist and one in training.CF score (1: mild, 2: moderate, 3: severe) was attributed to each exam by visual assessment.Motility at cine-MRI in stricturing Crohn's disease patients to evaluate stricture composition K. Beek 1 , K. van Rijn 1 , C. de Jonge 1 , F. de Voogd 1 , C. Buskens 1 , A. Mookhoek 2 , E. Neefjes-Borst 1 , K. Horsthuis 1 , J. Tielbeek 3 , G. D'Haens 1 , K. Gecse 1 , J. Stoker 1 ; 1 Amsterdam / NL, 2 Bern / CH, 3 Haarlem / NL 2Athens / GR Purpose: Results: Good interobserver agreement for both CF volume (71%) and fat wrapping distribution (74%) was observed.MARIAs score 2 patients had mostly CF score 1, whereas FWD was mostly significant.With MARIAs score 5, moderate FWD was most prevalent combined with CF score 3.No statistically significant association was found between CF score orFWD and MARIAs  score>2 (p=0.155 and p=0.573, respectively).Conclusion: Lack of significant correlation between CF and MARIAs score >2 suggests that CF alone may not act as a definite indicator of degree of CD severity.SS 5.5 Volumetric measurement of terminal ileal Crohn's disease by MR enterography: A feasibility study S. Kumar 1 , N. Rao 2 , A. Bhagwanani 3 , T. Parry 1 , M. Hameed 1 , S. Rahman 1 , H. Fitzke 1 , J. Holmes 1 , B. Barrow 1 , A. Bard 1 , A. Menys 1 , D. Bennett 4 , S. Mallett 1 , S.A. Taylor 1 ; 1 London / UK, 2 Coventry / UK, 3 Frimley / UK, 4 Cambridge, MA / US Purpose: MR enterography (MRE) interpretation of Crohn's disease (CD) is subjective and uses 2D analysis.We evaluated the feasibility of volumetric measurement of terminal ileal (TI) CD on MRE compared to endoscopy and simplified MAgnetic Resonance Index of Activity (sMARIA), and the responsiveness of volume to biologics.Material and Methods: CD patients with MRE and contemporaneous CD endoscopic index of severity-scored ileocolonoscopy were included.A centre line was placed through the TI lumen defining the diseased bowel length on the T2-weighted non-fat saturated sequence, used by two radiologists to independently segment the bowel wall to measure volume.In phase 2, we measured disease volume in patients treated with biologics, who had undergone pre-and post-treatment MRE, with treatment response classified via global physician assessment.Conclusion: Volumetric measurement of TI CD by MRE is feasible, related to endoscopy and sMARIA activity, and responsive to biologics.Diagnostic value of MR and CT enterography in postoperative recurrence of Crohn's disease: A systematic review and meta-analysis M. Chavoshi, S. Zamani, S. Kolahdoozan, A. Radmard; Tehran / IR Purpose: To assess the diagnostic yield of enterography techniques in postoperative recurrence (POR) of Crohn's disease (CD).Material and Methods: A systematic electronic bibliographic databases search was conducted.The inclusion criteria of published original articles were utilized MR enterography (MRE) or CT enterography (CTE) after an ileocolonic resection; documented POR by ileo-colonoscopy; provided crude data of diagnostic performance.The POR was defined as Rutgeerts' score≥i2.A random effect model was used for the analysis of diagnostic performance.The relative risk and diagnostic value of each imaging parameter were calculated.p=0.095).No difference was found in motility between inflammatory (n=4; 70.8AU [46.9-80.3]),mixed(n=17;69.)andchronicstrictures(n=12;69.1AU[61.2-152.7]).Strictures<5 cm (which were all mixed or chronic) had a higher motility in pre-stricturedilatation (n=5;]) compared to pre-stricture dilatation of strictures>5 cm (n=5; 108.1AU [72.0-174.0];p=0.03).Conclusion:Motility in pre-stricture dilatations is higher in both chronic strictures and strictures <5cm.An explanation for this phenomenon could be the increased wall stiffness in strictures with chronicity.Motility in pre-stricture dilatations could serve as a biomarker of stricture composition.SS 5.9 MRI-based average T2 signal as a non-invasive measure of fibrosis in enteric Crohn's disease I. Naim 1 , C. Hoad 2 , C. Clarke 2 , A. Mukherjee 2 , N. Jinnah 2 , P. Gowland 2 , O. Mougin 2 , A. Bard 1 , A. Menys 1 , G.W. Moran 2 ; 1 London / UK, 2 Nottingham / UK Purpose: In Crohn's disease (CD), 10% of patients present with fibrostenosis with a further 10% progressing from inflammatory to a fibrostenotic disease behaviour over 7 years.40% of fibrostenotic CD patients need surgery at 5 years compared to ~10% with inflammatory disease.T1, T2, diffusionweighted imaging, motility and bowel volumes have shown promise in the non-invasive measure of fibrosis.This study investigates the potential of MRI measures as non-invasive biomarkers for fibrosis in CD. mation scores (r(17)=.493,p=.045).Conclusion: The correlations between T2 signal, stricture volume, and inflammation scores suggest MRI measures, particularly those from GI-Seg, as promising biomarkers for fibrosis and inflammation in CD.However, further research is needed to identify markers specifically indicative of fibrosis to differentiate it from inflammation.
Comparison of LI-RADS treatment response algorithm and imaging features in triple-arterial MR acquisition in patients with HCC after locoregional therapies A. Blandino 1 , F. Khorasanizadeh 2 , G. Bini 1 , F. Matteini 1 , R. Cannella 1 , G. Brancatelli 1 ; 1 Palermo / IT,2Tehran / IR Purpose: To compare the liver imaging reporting and data system (LI-RADS) treatment response algorithm and imaging features in MRI acquired with a triple-arterial phase protocol in patients with treated HCC.Material and Methods: A retrospective study was conducted on 71 MRIs of the liver in patients with history of HCC who underwent local-regional treatment (resection, transarterial chemoembolization and ablation).MRI examinations were acquired on a 1.5T (56.3%) or a 3T (43.7%) scanner using an extracellular (8.5%) or a hepatobiliary (91.5%) contrast agent with a triplearterial phase imaging protocol.Images were analyzed by two radiologists who attributed, for each arterial phase (AP), a LR-TR category, evaluated the imaging features (APHE, treatment-specific enhancement pattern, washout appearance), and presence of artifacts based on a 5-point scale.McNemar and Wilcoxon signed-rank test were used to compare differences in imaging features and artifact scores among the triple-AP, respectively.Results: A total of 54 (38 males, mean age: 72.2 years) patients with 71 posttreatment MRIs were included.APHE was significantly more on the second AP compared to the third AP (14.1% vs 5.6%, p=0.031).The second AP showed more commonly treatment specific enhancement pattern (8.5%, p values 0.250-1.000)andLR-TRviablecategory(16.9%, p value 0.063-0.727),withoutstatisticallysignificantdifferences.No significant differences were observed regarding the presence of artifacts (median 1 [interquartile range (IQR) 1-2] vs 1 [IQR 1-2] vs 2 [IQR 1-2]; p value 0.721-0.897).Conclusion: Although the three arterial phases acquired with a triple-arterial phase MRI protocol show similar frequency of LR-TR features, the second AP seemed to convey more information and it can detect more commonly APHE.This single-center retrospective study (October 2011 to March 2023) included consecutive patients with resectable Barcelona clinic liver cancer (BCLC) A/B HCC beyond Milan criteria undergoing upfront SR or neoadjuvant therapy.All images were independently evaluated by three blinded radiologists.In patients receiving upfront SR, an MRI-based Early Recurrence Outside Milan (EROM) score to predict early recurrence-free survival was developed via Cox regression analyses and compared with the BCLC and China Liver Cancer (CNLC) staging systems.Among patients treated with neoadjuvant therapy, the rates of drop-out from SR were compared between EROM-predicted high-and low-risk groups.Microvascular invasion (MVI) is an established adverse prognostic factor in HCC, but its assessment is subject to sampling errors and might be complemented by imaging.Therefore, we aimed to evaluate the incremental prognostic values of MRI-based peritumoral features to pathologically assessed MVI.Material and Methods: This single-center retrospective study (April 2011 to May 2023) included consecutive patients who underwent curative resection for solitary BCLC 0/A HCC and preoperative MRI.Three blinded radiologists independently evaluated the MRIs for five peritumoral features.Cox regression analyses were conducted to identify predictive factors of early (≤2 years) recurrence-free survival (RFS), and an MRI criterion (MRIC) was established.Results: 645 patients (median 53 years; 549 men) were included, 239 (37.1%) with MVI.At multivariable Cox analysis, MVI (HR, 2.45; P<0.001), portal venous phase peritumoral hypoenhancement (HR, 2.05; P<0.001) and T1 peritumoral hypointensity (HR, 1.51; P=0.03) were associated with early RFS.Therefore, the MRIC was considered positive if ≥one of these peritumoral MRI features were present.Patients with MVI-positive but MRIC-negative status showed similar cumulative 2-year RFS rate to those with MVI-negative but MRIC-positive status (55.9% vs. 60.4%,P=0.709),thusweregroupedtogether as "either positive".According to MRIC and MVI, patients were stratified into low-risk (both negative, n=360; 2-year RFS, 80.5%), intermediate-risk (either positive, n=192; 2-year RFS, 57.0%; P<0.001 against low-risk) and high-risk (both positive, n=93; 2-year RFS, 34.6%; P<0.001 against intermediate-risk) groups.Conclusion: MRI-based peritumoral features could complement pathologically assessed MVI for more effective early recurrence risk stratification in patients with solitary HCC.This retrospective study included 88 HCC patients who received sorafenib treatment after surgical resection.Immunohistochemistry was used to assess the expression of PD-L1.Texture features were extracted based on CECT.The related significant features of PD-L1 expression were determined by the logistic regression analysis.The diagnostic performance of texture features was assessed by the area under the curve (AUC).Cox proportional-hazards model and Kaplan-Meier analysis were employed to select predictive features associated with recurrence-free survival (RFS) and overall survival (OS).Imaging plays a crucial role in selection criteria for liver transplantation in early-stage HCC associated with cirrhosis.We sought to establish the accuracy of pre-transplant imaging by comparing imaging reports to explant histopathology following liver transplantation for HCC as well as determine the impact on survival.Material and Methods: All liver explant histopathology reports containing HCCs from January 2015 to December 2020 were cross-referenced with pretransplant imaging reports (multiphase CT and MR liver with Primovist).The number and size of HCCs were extracted and compared and other lesions not identified or mischaracterised were also noted.Two-year survival outcomes were analysed using Kaplan-Meier estimates and the log-rank test.Results: Out of 140 patients, 98 (70.7%) were within criteria, 35 (25%) were outwith criteria, 1 (0.7%) had an unclassifiable lesion and in 5 (3.6%) no malignancy was identified.19(14%)livers where found to have >5 HCCs.Of the 203 HCCs identified on explant pathology, 122 (60%) were definitively identified, 28 (14%) were indeterminate and 53 (26%) were not identified.The per-lesion sensitivity of pre-transplant imaging for HCC was 74% (including indeterminate lesions) and 18.5% for lesions <10mm.2-yearsurvivalwas 88.8%.Patients outwith transplant criteria with >5 HCCs (n=18, 13.4%) had the poorest survival at 77.8% (p= 0.009).Conclusion:A significant number of transplanted patients are outwith transplant criteria.The per-lesion sensitivity for HCC was very poor for lesions <10mm.This resulted in 19 explanted livers having multiple small HCCs with these patients having worse outcomes.There is a need for accurately identifying this cohort of patients to optimise outcomes in liver transplantation.All patients who underwent liver transplantation with the diagnosis of HCC from 2012 to 2023 and had follow-up surveys for more than 3 months were included.Demographic, clinical, laboratory, imaging, and histopathologic variables including alpha-fetoprotein level, and several eligibility criteria were extracted to evaluate factors related to post-transplant HCC recurrence.Kristic 1 , S. Poetter-Lang 1 , A. Messner 1 , N. Bastati-Huber 1 , R. Ambros 1 , J. Kittinger 1 , S. Pochepnia 1 , S. Venkatesh 2 , N. Kartalis 3 , A. Ba-Ssalamah 1 ; 1 Vienna / AT, 2 Rochester, MN / US, 3 Stockholm / SE Purpose: To validate ANALI scores with and without gadolinium (ANALIGd and ANALINoGd) and to compare their prognostic ability with the recently proposed potential functional stricture (PFS), all derived from unenhanced and gadoxetic acid-enhanced MRI (GA-MRI) in primary sclerosing cholangitis (PSC) patients.Material and Methods: Five readers scored intrahepatic bile duct change severity, hepatic dysmorphia, liver parenchymal heterogeneity, and portal hypertension on GA-MRI, including 3D-T2-MRCP to generate ANALIGd and ANALINoGd.They also evaluated 20-minute hepatobiliary-phase (HBP) images for PFS, i.e., absent contrast excretion in first-order bile ducts [i.
1 months for the AFPpositive group and 13.3 months for the AFP-negative groups).Conclusion: mRECIST was more indicative of pathologic response after combination therapy than RECIST 1.1.Integration of mRECIST with AFP or PIVKA-II responses allowed for accurate prediction of MPR and could support decision-making on subsequent curative-intent treatment.Purpose: To develop an MRI-based model for predicting early recurrence (≤2 years) or drop-out from surgical resection (SR) after neoadjuvant therapy in patients with resectable HCC beyond Milan criteria.Material and Methods: Purpose:Purpose: Overexpression of programmed cell death protein ligand-1 (PD-L1) could cause tumor resistance to sorafenib in HCC patients.Our study aimed to predict the expression of PD-L1 and prognostic outcomes of HCC patients who received sorafenib treatment after surgery using contrast-enhanced CT (CECT) texture signature.Material and Methods:Purpose:Factors predicting post-transplant HCC recurrence F. Salahshour, M. Nassiri-Toosi, M. Taher, A. Jafarian, N. Ayoobi yazdi, F. Jamil, M. Taherzadeh, M. Safaei, F. Azmoudeh-Ardalan, F. Ghavidel; Tehran / IR Purpose: Liver transplantation is a definite treatment for both HCC and endstage liver disease.Organ shortage and risk of post-transplant HCC recurrence necessitate adherence to some eligibility criteria.In this study, we aimed to evaluate factors related to post-transplant HCC recurrence.Material and Methods: e., left hepatic duct (LHD)/right hepatic duct (RHD)/common hepatic duct (CHD)/common bile duct (CBD)] or none at all vs normal biliary excretion, i.e., no functional stricture (NFS).Inter-and intrareader agreements were assessed and Kaplan-Meier curves were generated for survival analysis.Cox regression analyses were performed to evaluate association between ANALINoGd, ANALIGd, PFS and clinical scores, labs and outcomes.Results:For 123 patients, mean age 40.5 years, Fleiss' kappa agreement was almost perfect-(ϰ=0.81)forPFS,but only moderate-(ϰ=0.55) for binary ANALINoGd.For binary ANALIGd, the agreement was slightly better on HBP (substantial-ϰ =0.64) than arterial phase (AP) (moderate-ϰ =0.53).Conclusion: Gallbladder polyp surveillance in patients with PSC has improved but remains suboptimal.Over 10 years, 7 patients (5%) developed gallbladder polyps, and of the four removed, all showed malignancy.SS 7.3Radiomics features for risk stratification in primary sclerosing cholangitis: A proof-of-concept study C. Maino 1 , L. Cristoferi 1 , P. Franco 2 , E. De Bernardi 1 , M. Carbone 1 , D. Ippolito 2 ; 1 Milan / IT, 2 Monza / IT 1, C. Aubé 2 , A. Paisant 2 ; 1 Clichy / FR,2Angers / FR For all readers, and all lesion visualization parameters, the difference in mean of scores showed the non-inferiority of gadopiclenol to gadobutrol (lower limit of 95%CI between −0.23 and −0.13, above the non-inferiority margin [−0.35]).There were no significant differences in LBR between the two GBCAs for all 3 readers (p≥0.1).E% was higher with gadopiclenol for 1 reader (p <0.0001) and not significantly different for the 2 others.The readers reported no preference between the images with gadopiclenol and those with gadobutrol in the majority of cases (69.7% to 87.9% of the evaluations).Conclusion: Gadopiclenol at 0.05 mmol/kg is non-inferior to gadobutrol at 0.1 mmol/kg for contrast-enhanced MRI of the liver.
the mean values of each case across the mean values from each of the three levels per case).Conclusion: Deformable registration significantly improves the internal and external contour agreements over rigid point-based registration.
Integrating radscore with mrTRG represented a significant advancement in the re-staging of rectal cancer.This approach not only improves the accuracy of pCR prediction but also ensures greater consistency among radiologists, suggesting that advanced imaging analytics like radscore can substantially enhance clinical decision-making in rectal cancer treatment.
1, J.-M.Kim 1 , H.-J. Chung 1 , Y. Chang 1 , R. Kwon 1 , J. Kang 1 , Y. Kim 1 , J.H. Choi 1 , H.-S. Jung 1 , G.-Y. Lim 1 , J. Ahn 1 , S. Wild 2 , C.D. Byrne 3 , S. Yoon 1 , S. Ryu 1 ; 1 Seoul / KR,2Edinburgh / UK, 3 Southampton / UK Our findings showed that liver fat fraction's AUROC for diagnosing fatty liver was 0.809 in men and 0.791 in women.Abdominal aortic calcification effectively predicted a high coronary artery calcium score, with AUROCs of 0.837 in men and 0.946 in women.In addition, the AUROCs for detecting class II sarcopenia and low bone density [T-scores <−2.5, based on dual-energy X-ray absorptiometry (DXA)] were notably high, with 0.900 in men and 0.882 in women for sarcopenia, and 0.905 in men and 0.918 in women for bone density.Conclusion:The study highlights the significant role of automated CT-derived imaging markers in the early detection and management of cardiometabolic risks.Markers such as liver fat fraction, abdominal aortic calcification, and muscle area are effective in predicting various cardiometabolic conditions.These findings endorse the use of CT-derived markers in routine health screenings, offering a potential pathway to improved patient outcomes through early intervention and targeted care for cardiometabolic health risks.In the T2* mapping examination, while cardiac iron accumulation was not observed, iron deposition in the liver was detected in 16 patients.When patients with iron accumulation were excluded, the average liver T1 relaxation time was measured as 626.56±61.45and the ECV value as 40.4±7.24;these values were found to be statistically significantly higher compared to the control group (p=0.000).Furthermore, in the patient group, the average myocardial T1 time was measured as 1030.91 ms and the ECV value as 31.73±3.1,also statistically significantly higher than the control group (p=0.002).Conclusion: Our study revealed an increase in liver and myocardial native T1 and ECV values in patients with SCD compared to the control group.The elevation in native T1, indicating an increase in conditions such as edema and fibrosis, along with the correlated rise in ECV values, a reliable marker of collagen content in the tissue, signifies the development of liver and myocardial fibrosis in individuals with SCD.We believe that mapping methods capable of simultaneously demonstrating iron accumulation through T2* mapping and fibrosis through T1 and ECV measurements can be employed in standard screening and follow-up, potentially reducing the need for biopsy.From January 2022 to December 2023, the option of WB-MRI was added as an adjunct diagnostic tool to the routine clinical workup, including CT, fluorodeoxyglucose positron emission tomography (FDG-PET)/CT, lab tests and biopsies for ACUP patients in our institution.The choice of whether to perform an MRI was discussed by a multidisciplinary team and guided by all available clinical information (e.g. if the primary tumour could likely be suspected to be located within the abdomen/pelvis).We analyzed the impact of WB-MRI in terms of primary tumour identification and detection of additional metastatic sites.
1, M. Ri 2 , E. Koltsakis 2 , E. Stenqvist 2 , G. Kalarakis 2 , E. Boström 2 , A. Kechagias 3 , I. Rouvelas 2 , A. Tzortzakakis 2 ; Surgery in combination with chemo/radiotherapy is the standard treatment for locally advanced esophageal cancer.Even after the introduction of minimal invasive techniques, esophagectomy carries significant morbidity and mortality.One of the most common and feared complications of esophagectomy is anastomotic leakage (AL).The aim of our work was to develop a multimodal machine learning model combining CT-derived and clinical data, for the prediction of AL following esophagectomy for esophageal cancer.Material and Methods: 471 patients were prospectively included (Jan 2010-Dec 2022).Preoperative CT was used to evaluate coeliac trunk stenosis and vessel calcification.Variables including demographics, disease stage, operation details, tumour histology, postoperative C-reactive protein (CRP) and stage were combined with CT data to build a model for AL prediction.Data were split into 80:20% for training:testing, and a XGBoost model was developed with 10-fold cross-validation and early stopping.Receiver operating characteristic (ROC) curves and respective areas under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and F1-scores were calculated.Results: 117 patients (24.8%) exhibited post-operative AL.The XGboost model achieved an AUC of 79.2% (95% CI 69%-89.4%)withspecificity of 77.46%, sensitivity of 65.22%, PPV of 48.39%, NPV of 87.3% and F1-score of 56%.SHapley Additive exPlanation (SHAP) analysis showed the effect of individual variables on the result of the model.Decision curve analysis showed that the model was particularly beneficial for threshold probabilities between 15% and 48%.Conclusion:In conclusion, a clinically relevant multimodal model can predict AL, being especially valuable in cases with otherwise low clinical AL probability.Prevalence of CT-detected extramural vascular invasion in gastric adenocarcinoma and its correlation with other known prognostic factors A. Chandramohan, H.V. Reddy, D. Masih, A. Singh, I. Samarasam; Vellore / IN Purpose: To study the prevalence of extramural vascular invasion (ct-EMVI) in gastric adenocarcinoma (GA) and its association with other known prognostic factors.Material and Methods: This is an IRB-approved retrospective study of patients with GA who underwent staging CT between January 2021 and December 2022.Two experienced radiologists reviewed the staging CT for ct-EMVI and its grade, tumor location, thickness, perigastric nodes, and metastases.Grade 3 and 4 EMVI on CT were reported as ct-EMVI positive.The restaging CT was reviewed for y-ct-EMVI and y-ct-TNM stages for those who underwent neoadjuvant chemotherapy.Peritoneal fluid cytology, staging laparoscopy, and surgical histopathology findings were documented.We studied the association between ct-EMVI and other imaging findings on staging and restaging CT and surgical histopathology findings.Results: 191 patients (140 males, 51 females) with a mean age of 53 ± 9 (range 23 to 93) years were included.82.2% had poorly differentiated GA.The majority (95.9%) had T3 (n=34) and T4 (n=118) disease on baseline CT.The prevalence of ct-EMVI on staging CT was 65% (n=124) with 34% and 86% of T3 and T4 stage GA being ct-EMVI positive, respectively.There was a significant association between ct-EMVI and ct-T, N, and M stages, tumor thickness and extent, surrounding organ infiltration, peritoneal metastases, and response to neoadjuvant chemotherapy (p<0.05).Conclusion: ct-EMVI is common (65%) among patients with advanced GA and was significantly associated with TNM stage, peritoneal metastases, and response to neoadjuvant chemotherapy.Association of chronic statin use, myopenia, myosteatosis and major morbidity in surgical patients with upper GI cancer P. Franco, C. Maino, T. Giandola, C. Talei Franzesi, D. Gandola, M. Cereda, L. Gianotti, D. Ippolito; Monza / IT Purpose: Derangements of body composition affect surgical outcomes.Chronic statin use may induce muscle wasting and impair muscle tissue quality.The aim of this study was to evaluate the association of chronic statin use, skeletal muscle area (SMA), myosteatosis and major postoperative morbidity.Material and Methods: Between 2011 and 2021, patients undergoing pancreatoduodenectomy or total gastrectomy for cancer, and using statins since at least 1 year, were retrospective studied.SMA and myosteatosis were measured at CT scan.The cutoffs for SMA and myosteatosis were determined using receiver operating characteristic (ROC) curve and considering severe complications as the binary outcome.The presence of myopenia was defined when SMA was lower than the cutoff.A multivariable logistic regression was applied to assess the association between several factors and severe complications.Results: After a matching procedure (1:1) for key baseline risk factors [American Society of Anaesthesiologists (ASA), age, Charlson comorbidity index, tumor site, and intraoperative blood loss], a final sample of 104 patients, of which 52 treated and 52 not treated with statins, was obtained.The median age was 75 years, with an ASA score ≥ 3 in 63% of the cases.SMA (OR 5.119, 95% CI 1.053-24.865)andmyosteatosis(OR4.234,below the cutoff values were significantly associated with major morbidity.Statin use was predictive of major complication only in patients with preoperative myopenia(OR 5.449,.Conclusion: Myopenia and myosteatosis were independently associated with an increased risk of severe complications.Statin use was associated with a higher risk of having major morbidity only in the subgroup of patients with myopenia.